Actually, you can make a pretty strong build with just Factions skills. The only strong skills that you're missing is Critical Agility (which is a PvE skill) and maybe Way of the Assassin (which is a Critical Strikes elite). You also can't maintain Shadow Form because you won't have Deadly Paradox (which makes your Assassin skills recharge 33% faster).
But for now, try this:
Jagged Strike, Fox Fangs, Death Blossom, Critical Eye, Flashing Blades (elite).
The other 3 skills can really be anything, just mess around with it.